Use of a monolithic ceramic capacitor for decoupling in the vicinity of a CPU may cause an oscillation due to parallel resonance in a circuit and increase impedance, because the equivalent series resistance (ESR) of the monolithic ceramic capacitor is very low. In such a monolithic ceramic capacitor, therefore, the ESR is sometimes required to be controlled in the range of several tens to several thousands of milliohms. In response to this demand, one proposed monolithic ceramic capacitor includes an external electrode that also functions as a resistance element.
Thus, International Publication WO 2006/022258 (Patent Document 1) describes a monolithic ceramic capacitor that includes an internal electrode containing Ni or a Ni alloy, in which an external electrode has sufficient reduction resistance and includes a resistive electrode layer, which includes an In—Sn complex oxide (ITO) reactive to the Ni or Ni alloy contained in the internal electrode and a glass component.
According to the technique described in Patent Document 1, advantageously, the external electrode can have sufficient resistance, a conductive layer for continuity between the external electrode and the internal electrode is not needed under the resistive electrode layer, and a protective layer for protecting the resistive electrode layer does not require an expensive non-oxidizable metal.
Patent Document 1 also discloses that part of ITO is substituted by Ag, Al2O3, or ZrO2 to control the resistance.
However, it was found that an increase in the substitution rate of Ag, Al2O3, or ZrO2, for example, to increase the resistance may lead to the occurrence of blisters due to over-sintering or reduced denseness due to insufficient sintering. Even if the resistive electrode layer has a constant resistance, the ESR may easily vary with the dimensions of a ceramic laminate, which is a component of the monolithic ceramic capacitor, the thickness of the resistive electrode layer, and the number of laminated layers in the internal electrode. Thus, resistive pastes having different substitution rates of Ag, Al2O3, or ZrO2 for different designs, such as the dimensions of the ceramic laminate, the thickness of the resistive electrode layer, and the number of laminated layers in the internal electrode, must be prepared to achieve a desired ESR.    [Patent Document 1] International Publication WO 2006/022258